Star Wars has often been very much about the Jedi and the Sith. Luke's discovery of his heritage as the son and later apprentice of a Jedi, and his grand finale battle with the Sith Master Palpatine, can be seen as the over-arching story of the entire Original Trilogy. The prequels even more overtly deal with the Jedi--hardly a major character exists who isn't a Force-using Knight of some kind or another, and the story is designed to be told from the perspective of the Jedi. Or at least some specific Jedi--Obiwan, Annakin, etc. The Clone Wars, which is the last major outlet for "true canon" as far as my setting iteration is concerned, is also primarily told from the perspective of the Jedi, and is about their doings.
This focus partially obscures some things, though. In the Original Trilogy, Luke, Vader, the Emperor, and to a lesser extent Ben Kenobi and Yoda are the only knights that make any appearance at all. Many other characters are significant characters, like Han, Leia, the droids, etc. Lucas famously over-committed the reality of the situation when he said that the point of view characters are the droids themselves. What's important here is that non-Force using characters can be pretty darn important to Star Wars, and in fact should be. You can see this in many episodes of the Clone Wars too--while overall the series is about the Jedi--especially Ahsoka and Annakin, many episodes barely feature them, or even don't feature any Jedi, Sith or otherwise at all. And presumably, the Star Wars: Rebels series will focus on them even less (although I'd be surprised if some underground, lingering Jedi of some sort or another don't still show up from time to time. And the Inquisitor is obviously a Sith assassin. And let's not forget that since Ahsoka left the Jedi Order, it's concievable that she'd survive the Jedi Purge and still be kicking around during the Rise of the Empire era.)
Sometimes the writers (including George Lucas himself) lose sight of this, and make the Jedi both too good, too capable, and too important for anyone to stand up to them in any meaningful sense. But other times, it's quite clear that non-Force using characters can be the equal to a Jedi when they need to be. Jango Fett fought Obiwan to a standstill in Attack of the Clones. Highly skilled bounty hunters like Sugi, Embo, Cad Bane, and others showed themselves equal to the Jedi (or Sith) when they needed to be. Pre Viszla's duel with Darth Maul showed him to be highly capable, and he might have won, even though Maul was one of the most dangerous combatants in the galaxy.
Of course, in order to do this, these characters almost become superheroes themselves. It's actually easy to see Embo as an alien Captain America, and Sugi as an alien Black Widow. The Mandalorians, with their tricked out supercommando battle armor, almost seem to be Iron Man like at times.
But maybe this is the lesson in how to run Star Wars. The action is over-the-top. It is extremely swashbucklery, and borders on overt comic book like in tone and feel, quite frequently, even. It's easy to justify this superheroic action with the Jedi, because after all, they have the Force with them, which makes them superheroes. But when the plot dictates, anyone else can be just about as capable, either through intense training, fancy equipment, or a combination of the two. In in reality, that means that highly capable non-Force users should be like Batman, Hawkeye, the Black Widow, or other characters, who while lacking overt superpowers, routinely are able to go toe-to-toe with actual superheroes as needed by the demands of the plot of the stories that they're in.
When in doubt, and since it's now in Free-To-Play mode, check out The Old Republic. Only half of the character classes are Force Users, and the Bounty Hunters, Scoundrels, Imperial Agents and Republic Troopers don't suffer because of their lack of the Force. Rather, they're great examples of what Star Wars can be when knights aren't around.
And, to counter this, Star Wars is filled with mooks. By this, I mean antagonists who aren't really meant to be terribly threatening, especially not on an individual level. From battle droids to stormtroopers, part of what makes the heroes seem so cool is the fact that they can mow through mooks with relative ease. Not impunity, but relative ease. Mooks don't have any hit points. Any hit at all and they go down. They slow down the heroes. They can threaten the heroes in large numbers. But to some degree, the whole point of mooks is to make sure that the heroes feel heroic.